To examine the predictive value of body-self unity and the cognitive evaluation of illness on self-esteem. The study has been performed among patients with a rheumatic disease and took place in the waiting room of the department of rheumatology at a hospital. An instrument has been developed to measure body-self unity. The Illness Cognition Questionnaire (ICQ) and the Rosenberg self-esteem scale (RSES) have been used to assess the illness and selfevaluation. Demographic and disease variables are the control variables. The body experience questionnaire reveals a two factor structure with good reliability. A hierarchical regression analyses shows that psychological factors can mediate bodily impediments of the disease on self-esteem, with the largest contribution of body-self unity. Altogether the variables in the proposed model can predict 50% of the variance in selfesteem for patients with a rheumatic disease. Body-self unity plays a major role in the self-evaluation of a patient and is of greater importance for the self-esteem than the physical impact of the disease. Re-establishment of the body-self unity can therefore be an important means to improve the patients wellbeing. This can be most helpful in case of a chronic disease, where the cause of a battle between body and self will always be present.